The longer its exposed to air/moisture the more problems can occur.

These are all signals that there may have been an issue with moisture. 

If you are talking about the crack between the facia bricks and the rest of the house, my opinion; the crack is minor, however you need to fix the stucco exterior wall to cover the area where it fell off or you could have a moisture problem in your house.

When a tenant leaves a unit requiring more than normal cleaning, I have learned to hire out and have the company itemize standard charge and then excessive charges.  

They did not even sweep the floors, the appliances which they received brand new are now filthy, shower has growth from moisture and the windows are dusty with dead flies on window seals.

I was able to get under the house and look around. the front foundation wall is bowing badly and in poor condition with moisture getting through.

Can someone post their opinion if the Landlord (homeowner) can actually withhold some of the deposit.The Landlord will return the Security Deposit at the end of this tenancy, less such deductions as provided in this Lease but no deduction will be made for damage due to reasonable wear and tear nor for any deduction prohibited by the Act.During the Term of this Lease or after its termination, the Landlord may charge the Tenant or make deductions from the Security Deposit for any or all of the following:Repair of walls due to large nails or any unreasonable number of holes in the walls including the repainting of such damaged walls;Repairing cuts, burns, or water damage to tile, linoleum, carpet and other areas;Repainting required to repair the results of any other improper use or excessive damage by the Tenant;Repairs and replacement required where windows are left open which have caused plumbing to freeze, or rain or water damage to floors or walls; andReplacing damaged or missing doors, windows, screens, mirrors or light fixtures;Any other repairs or cleaning due to any damage beyond normal wear and tear caused or permitted by the Tenant or by any person whom the Tenant is responsible for;Unplugging toilets, sinks and drains;Any other purpose allowed under this Lease or the Act.

I let the grout dry to long before I wiped off the excess and kind of panicked when I couldn't get excess grout off.

A safe occupancy level for a three bedroom is seven people (two per bedroom, plus one additional), so it's not safe, it's excess wear-and-tear on the rental, and they are violating it even more by adding three more than you agreed to allow.

If you have excess cash flow place it in a liquid account like PTY (8+) consistent yield over many years thru good and bad markets.